Ophthalmological devices capable of performing an objective measurement for a subject's eye are known. For example, 1 Japanese Unexamined Patent Application Publication No. 2006-187482 discloses an ophthalmological device that obtains a spherical power, an astigmatic power, and an astigmatic axis angle of the subject's eye, by analyzing a ring image acquired by projecting a ring-shaped light flux for measuring an ocular refractive power onto a fundus of the subject's eye and detecting returning light thereof. 
However, in case that a diseased site exists on the fundus of the subject's eye, when the ring-shaped light flux for measuring is projected onto the diseased site, distortion or deformation of the shape of the ring image acquired by detecting the returning light from the fundus increases. Thereby, there is a problem that the accuracy of the obtained spherical power, astigmatic power, and astigmatic axis angle of the subject's eye decreases. Such variations in objective measurement values may also influence the accuracy of subjective inspection performed by reflecting the objective measurement values.
Further, the distortion of the shape of the ring image and the like may be caused not only by the diseased site of the fundus but also by the ocular media including a crystalline lens. Therefore, it is sometimes impossible to specify the reason why the accuracy of the obtained spherical power, astigmatic power, and astigmatic axis angle of the subject's eye decreases, merely by analyzing the ring image.
An ophthalmological device according to embodiments comprises an objective lens, an objective measurement optical system, an interference optical system, and an image forming unit. The objective measurement optical system irradiates light onto a subject's eye via the objective lens and detects returning light from the subject's eye. The interference optical system splits light from a light source into reference light and measurement light, projects the measurement light onto the subject's eye via the objective lens so as to overlap at least part of an area of the irradiated light at the subject's eye by the objective measurement optical system, generates interference light between returning light of the measurement light and the reference light, and detects the generated interference light. The image forming unit forms a tomographic image of the subject's eye based on a detection result of the interference light by the interference optical system.
An ophthalmological inspection system according to the embodiments comprises a left inspection unit for inspecting the subject's left eye and a right inspection unit for inspecting the subject's right eye, wherein at least one of the left inspection unit and the right inspection unit includes the ophthalmological device according to the embodiments.
With an ophthalmological device and an ophthalmological inspection system according to the embodiments, accuracy of an objective measurement value can be improved.